“It is abundantly clear that a total review of all intelligence programs is necessary so that members of the Senate Intelligence Committee are fully informed as to what is actually being carried out by the intelligence community.” That was Sen. Dianne Feinstein, D-Calif., the chair of the Senate Intelligence Committee, blasting U.S. spies for not fully informing congressional overseers about one of the more contentious intelligence programs in recent memory. But that wasn’t Feinstein talking about CIA interrogations, which was the subject of a blistering tirade this week that accused the CIA of violating the Constitution. That was Feinstein in October 2013, blasting the NSA for monitoring the phone calls of key U.S. allies, notably German Chancellor Angela Merkel. One NSA official was so taken aback by the vehemence of a long-reliable ally that he remarked, “We’re really screwed now.”

But Feinstein’s bark was far worse than her bite. Shortly after her remarks, the senator proposed a bill that would have allowed the NSA to continue its bulk collection of Americans’ phone records, by far the most controversial and legally questionable of all the secret NSA programs revealed by former contractor Edward Snowden. Now, after her unprecedented attack Tuesday that accused the CIA of spying on Senate staffers and impeding an investigation into alleged torture, Feinstein has to make a choice: stand her ground by taking concrete steps to rein in the agency or again back away from her most incendiary charges and allow another spy agency to continue with business as usual.

If she chooses to play hardball, Feinstein can make the tenure of CIA Director John Brennan a nightmare. From her perch on the intelligence committee, she could drag top spies before the panel for months on end. She could place holds on White House nominees to key agency positions. She could launch a broader investigation into the CIA’s relations with Congress and she could hit the agency where it really hurts: its pocketbook. One of the senator’s other committee assignments is the Senate Appropriations Committee, which allocates funds to Langley. Following last year’s disclosure by Edward Snowden that the CIA’s black budget request of $14.7 billion for 2013 surged past every other spy agency, it may be in for a haircut. But whether Feinstein will use any of the tools in her toolbox is far from certain.

Former intelligence officials and congressional staffers said Feinstein’s nearly 40-minute-long speech is the clearest indication yet that the CIA’s relationship with its Senate overseers has reached a historic low point. Going forward, the senator could use her position on both the intelligence committee and the appropriations committee to deny funds for CIA programs, the former officials said. She could also place holds on executive branch nominations until the CIA answers more questions about its alleged meddling in the committee’s investigation.

“I have asked for an apology and a recognition that this CIA search of computers used by its oversight committee was inappropriate,” Feinstein said on the Senate floor. “I have received neither.”

And she shouldn’t expect to. In remarks at the Council on Foreign Relations Tuesday, a little more than an hour after Feinstein’s speech, CIA Director John Brennan categorically dismissed allegations that the CIA had inappropriately or illegally monitored committee staff.

“I think a lot of people who are claiming that there has been this tremendous sort of spying and monitoring and hacking will be proved wrong,” Brennan said. But he gave no indication of when, or if, the CIA might be coming forward with its own version of events.

Spokespersons for the CIA and Feinstein didn’t respond to requests for comment.

The political path forward appears rocky. Feinstein also alleged this week that the CIA claimed the White House had once instructed the agency to remove documents that the committee staff had already been cleared to see, raising anew the question of whether the White House intervened in a dispute between the CIA and the committee.

But for all the angry recriminations between Langley and Capitol Hill, both sides may find themselves locked in a standoff, one that may ultimately be settled by an official investigation.

The Justice Department is reportedly looking into whether the CIA inappropriately monitored congressional staff, as well as whether those staff inappropriately accessed documents that lay behind a firewall that segregated classified information that the CIA hadn’t yet cleared for release. And according to reports, the FBI has opened an investigation into committee staff who removed classified documents from the CIA facility and brought them back to the committee’s offices on Capitol Hill. Those documents were created after the interrogation program ended and thus technically fall outside the scope of the committee’s inquiry, the CIA contends. Unsurprisingly, Feinstein thinks those documents are fair game.

Feinstein defended their removal this week, and said staff transported the material by the book, obeying all rules about handling classified information. “When the staff found a document that was particularly important or that might be referenced in our final report, they would often print it or make a copy of the file on their computer so they could easily find it again,” she said. The material in dispute remains secured in the committee’s offices in the Hart Senate Office Building, she said.

Former intelligence officials said now that the dispute is under the review of law enforcement, the matter will take on a life of its own. Investigators will likely interview committee staff as well as CIA employees to determine whose side of events is accurate, or if the truth lies somewhere in between. And to the extent that the matter is the subject of an ongoing investigation, both sides may hold their public fire and refrain from any further accusations.

“I don’t know that either Brennan or Feinstein have much of a move to make,” said a former CIA liaison to Congress. “It’s up to the FBI and the Justice Department now to make up their minds whether there’s anything to these accusations.” The former official noted that the real dispute is ultimately not with Brennan and Feinstein so much as their staff, who are giving their version of events to their bosses. Undoubtedly, the two leaders are looking to them now for answers.

“John’s not a careless guy,” the former official said. “He’ll hammer at his congressional affairs staff and demand to know what happened. And I’m sure Feinstein has sat down with whomever removed those documents and asked them, ‘What did you do?’ “